You may have only paid $50 for your smartphone on subsidy, or even received it for free after inking a two-year service agreement with your wireless carrier. It's actually worth much more than what you bought it for -- several hundred dollars more -- making these easily swiped handsets mighty attractive to thieves. It's become a big problem in certain areas, prompting California law makers to push for a cell phone "kill switch."

Activating a remote kill switch would render the smartphone unusable, thereby making it a little more difficult for thieves to sell. In turn, mandatory kill switches on all smartphones would then make them far less attractive to crooks, at least in theory.

California State Senator Mark Leno, a Democrat, is expected to introduce a bill requiring all smartphones and tablets sold in his state to have a kill switch, The New York Times reports. Companies that sold phones without one could be fined up $2,500 per device.

"With robberies of smartphones reaching an all-time high, California cannot continue to stand by when a solution to the problem is readily available," Senator Leno said in a statement. "Today we are officially stepping in and requiring the cellphone industry to take the necessary steps to curb violent smartphone thefts and protect the safety of the very consumers they rely upon to support their businesses."

Smartphone theft is particularly prominent in metropolitan areas. For example, there were 2,400 cell phones stolen in San Francisco last year, up 23 percent from 2012. Sharp rises have also been noticed in places like New York and Washington D.C. However, mobile carriers aren't in favor of kill switches, preferring instead to sell you insurance.